30 
BULLETTX 244, U. S. DEPARTMENT OF AGRICULTURE. 
young shortleaf and erroneously mistaken for true annual rings of 
growth. 
Diameters throughout this bulletin, unless otherwise stated, are 
measured at breast height (4$ feet above the ground). Table 10 
shows the diameter growth based on age for the Piedmont region of 
North Carolina and for western Arkansas. The tables may be con- 
sidered as broadly applicable to large areas within the two specified 
regions, since differences in growth over large areas are not important 
except as caused by local variation in quality of situation. 
Table 10. — Diameter growth of shortleaf pine, on the basis of age, in Arkansas and North- 
Carolina. 1 
WESTERN ARKANSAS. 
Age (yeaxs). 
Diameter breast high. 
Age (years). 
Diameter breast high. 
Maximum. Average. 
Minimum 
Maximum. 
Average. 
Minimum. 
20 
Inches. 
7.2 
8.6 
9.9 
11.0 
12.0 
12.8 
13.6 
-14.4 
15.1 
15.7 
16.3 
16.9 
17.5 
18.0 
Inches. 
5.7 
7.0 
8.1 
9.1 
10.1 
10.9 
11.7 
12.3 
12.9 
13.5 
14.0 
14.5 
15.0 
15.5 
Inches. 
4.3 
5.4 
6.4 
7.4 
8.2 
9.0 
9.7 
10.3 
10.8 
11.3 
11.8 
12.2 
12.6 
12.9 
90 
Inches. 
18.5 
19.0 
19.4. 
20.3 
21.1 
21.7 
22.3 
22.8 
23.2 
23.6 
23.9 
24.1 
24.3 
Inches. 
15.9 
16.3 
16.6 
17.3 
17.8 
18.3 
18.7 
19.0 
19.3 
19.6 
19.7 
19.9 
20.1 
Inches. 
13.3 
25 
95 
13.6 
30 
100 
13.8 
35 
110 
14.2 
40 
120 
14.6 
45 
130 
14.9 
50 
140 
15.1 
55 
150 
15.3 
60 
160 
15.4 
65 
170 
70 
180 
15.6 
75 
190 
15.7 
80 
200 
15.8 
85... 
PIEDMONT REGION, NORTH CAROLINA. 
2.0 
0.9 
5.9 
3.0 
9.2 
4.9 
11.6 
6.3 
13.3 
7.5 
14.5 
8.4 
15.6 
9.2 
16.5 
9.9 
0.6 
1.2 
1.8 
2.4 
3.0 
3.5 
4.0 
45 
50 
55 
60 
65 
70 
75 
SO 
17.1 
10.5 
17.6 
11.0 
18.0 
11.4 
18.4 
11.7 
18.7 
12.1 
19.0 
12.4 
19.2 
12.7 
19.4 
13.0 
4.5 
5.0 
5.4 
5.8 
6.1 
6.4 
6.8 
7.1 
1 The table for Arkansas is based on breast-high diameter measurements of 2S5 trees and 34 trees repre- 
senting the average of even-aged plots; the North Carolina tabic is based on decade measurements on 332 
stumps, 26 to 89 years old. 
The close relation between tree density and growth in diameter is 
illustrated in Table 11, compiled from measurements on unit areas 
of different density of trees of a 30-year-old fully stocked shortleaf 
stand. In seven consecutive sample areas of one-tenth acre each, 
the size of the diameter class prevailing on each plot increased regu- 
larly with a corresponding regular decrease in the number of trees 
per acre. So far as is known this close relation holds true for all 
pure stands of shortleaf pine. 
